The present invention relates in general to the winding of textile yarns, filaments, or the like of natural, man made or synthetic materials, all referred to herein as "yarns", and more particularly to high speed precision winding of yarn packages on a precision winder machine having a propeller structure for guiding the yarn back and forth between the ends of the package during the winding process, and incorporating sensors and controls for regulating the propeller drive, the spindle drive for the yarn package, and down pressure drive to produce a highly uniform package which is free of ribboning effects when subjected to dying processes and the like.
Before the days of the continuous filament extrusion, texturizing, and similar high speed methods of yarn production, traditional traversing mechanisms for laying yarn on a package included a grooved scroll which either engaged the yarn directly or drove a yarn guide so as to cause it to carry out a reciprocatory traversing motion. Those mechanisms were limited as to their speed of operation and the uniformity of packages produced by such mechanisms.
Upon the more recent development of high speed yarn production methods, the demand was emphasized for winders having very much higher speeds of operation. One form of traversing mechanism proposed for such high speed winders included slot like yarn guides mounted on closely spaced driving members moving in opposite directions across the traverse so that the yarn was carried from one end of the traverse to the other by one yarn guide and was then transferred to another yarn guide so as to be carried back in opposite direction. This avoided inertial problems which were incident to use of a single yarn guide which moved in one direction and then the other, but created problems of yarn transfer from one guide to another.
While driving arrangements involving two guide members, one moving in one direction and the other in the opposite direction, have taken forms such as belt or chain drives for the yarn guides moving them in a straight line across the traverse, the use of rotary discs or blades which act as yarn guides moving across the traverse along and arc of a circle have come into wide use. These rotary discs or blade type yarn guides move in a continuous path with no abrupt changes in velocity or direction, so that the only inertia concerns presented are in connection with the inertia of the yarn itself at each reversal point. Care had to be taken, however, to maintain close control of the yarn as it is transferred from one yarn guiding blade or disc to another, in a manner which would avoid nipping action on yarn which may have an adverse effect on its quality. However full control over the yarn during transfer from one driving member to another is essential.
One of the widely used types of cross winding systems employed in the textile industry is of the type disclosed in U.S. Pat. No. 3,823,886 granted to Maschinenfabrik Scharer, which involve first and second yarn guides of a propeller or blade type rotatable and opposite directions about respective axes of rotation which are offset from each other, associated with respective substantially circular shaped guide members provided for each of the yarn guides, centered on the respective axes of rotation of the yarn guides so that the guide tracts intersect each other at a pair of diametrically opposite points for overlapping of the thread guides at these points. Other yarn traversing apparatus of this general type involving rotary blade or propeller type guides are disclosed in U.S. Pat. No. 4,561,603 of Dec. 31, 1985, U.S. Pat. No. 4,585,181 of Apr. 29, 1986 and U.S. Pat. No. 4,646,983 of Mar. 3, 1987 all granted to Barmag Barmer Maschinenfabrik A.G.
It has been customary, heretofore, for example in the Scharer winder machines, to attempt control of the winding in an effort to achieve uniformity throughout the wound packages by regulating a drive motor which drives the yarn guide blades or propellers and the package spindle. However, it has been found that this arrangement does not provide sufficient control of the various parameters affecting uniformity of the density of the yarn package to achieve the desired extent of yarn package uniformity wherein the packages are free of ribboning when subjected to the dying process, and which would have such uniformity all the way to the bottom of the package so that the innermost layers of yarn do not need to be discarded. I have found, however, that by providing separate drive motors providing separately controlled drive systems for the spindle drive, the propeller drive, and a down pressure drive, thus providing three independent motor systems that can be separately controlled, one can properly set and regulate the pitch and the tension during winding of the package so as to maintain the desirable yarn density or tension throughout the whole package, and ensures freedom from development of ribboning patterns during package winding, which are detrimental during the dying process.